A CHE is a ceramic heat emitter.

It really depends on the kind of setups you have. If you only have a couple glass setups, UTHs work well. If you are heating a large amount of tubs, flexwatt is much more economical. Both of these options must be used with a thermostat. If you want a thermostat that will control the heat of multiple sources, a johnson controls or ranco from reptile basics would be a good buy.